Electrode for reversible galvanic batteries.



N0 884,930. PATENTED APR. 14, 1908.

- E. W. JUNGN E. ELECTRODE FOR REVERSIBLE GALVANIC BATTERIES.

APPLICATION FILED SEPT. 20, 1904.

7450313 19658; fave 71 30 71 flaw JvM UNITED sTA'rns PATENT OFFICE.

ERNST WALDEMAR JUNGNER, OF KNEIPPBADEN, NORRKClPING, SWEDEN, ASSIGNOR T0 NYA AGKUMULATOR-AKTIEBOLAGET JUNGNER, OF STOCKHOLM, SWEDEN, A COMPANY.

ELECTRODE FOR REVERSIBLE GALVANIC BATTERIES.

No. ss4,93o.

Application filed September 20, 1904. Serial No. 225,235.

Specification pf Letters Patent.

Patented April 14, 1908.

To all whom it may concern:

Be it known that I, 'EnNsr WALDEMAR' JUNGNER, a subject of the King of Sweden, residing at Knei pbaden', N orrkoping, Sweden, have inventef certain new and useful Improvements in Electrodes for Reversible Galvanic Batteries;- and I do hereby declare the following to be a'full, clear, and exact description of-the invention, such as will enable others skilled in the art to which it apertains to make and use the same, reference iieing had to the accom anyingdrawings, and to letters or figures oi retere'nce marked thereon, which form a part of this specification. I 1

It is well known that in'accumulators employing an electrolyte; which remains unchanged during all conditions of working nonconductive or very badly conductive metallic oxids are used, for instance oxids. of mercury, copper, nickel, cobalt, iron, manganese, cadmium, bismuth, etc. or also the hydrates of these metals. Experiments have beenmade to make these oxids or hydrates conductive by mixing them with graphite. Then, of course, graphite is used in its natural occurrence t'. c. as crystalline graphite, which, when pulverized, will break up into flakes or scales. In consequence of their purity and form these flakes are more conductive and'have greater power of resistance against oxygen in stem 'nascentt, when subjected to electrolysis in alkali, than graphite 1n the form of small grains. It is, however, impossible, even with such graphite, to give the active mass a suiiicient conductivity. Thus, for instance, peroxid of lead as well as spongy lead have a conductivit that is many times greater than a mixture 0 crystalline graphite and a non-conductive metallic oxid.

The greatest inconvenience in accumula tors with invariable electrolyte is, without doubt, the great electric resistance. in the active masses, and'the present invention has for its object the remedying of'this inconvcniencc,"'totally or partly. The invention consists of a galvanoplastic coating of the graphite crystals with a thin sheet of some metal that is indifferent inthe electrolyte,

such as nickel for instance.

It is well known that the metals enerally have a. considerably greater conductivity than conductive kinds ofcarbon, and thus it 18 clear that amixlng in of metal coated generator.

graphite will have in consequence a considerably greater conductivity than if there is no such coating.

The galvanoplastic' coating in uestion may be made in the mannerdes cri ed below, with reference to the annexed drawing.

In an ordinary vessel (a) such as used for galvanoplastic .work containing for instance a common nickel bath, of any wellknown electrolyte used for nickel plating a basket (b) is placed, which consists of a very finenetwork of nickel and which is in conductory connection with the negative pole of an electric current enerator. Into the basket are placed the ilakes or crystals of graphite, which, of course, must be large enough not to fall down between the 'meshes of thenet. On the bottom of the vessel there is'an anode (n) of nickel, which is in conduct'ory connection with the positive ole of the current The nickel has the property of not being acted upon by oxygen 1n t 1e bath, 11. e. does not occlude this gas, and the coating is permanent. On the'other hand, platinum will occlude oxygen and fall as 'a. slime from the electrodes, and in a short time the conductivity 'will be greatly decreased.

Platinum will also occlude hydrogen which.

permeates .the' entire mass of the metal, while with nickel the surface of the lating only is affected by the'hydrogen, not t8 Now, if a' feeble electric current isconducted through the bath for some time, the flakes of graphite will gradually et a beautifully shining sheet of nickel. I 11 order to efiect the greatest ossible uniformity of the nickel-plating, the ath should be stirred ever and anon. The nickelplated graphite obtained in this manner, will of cou se, have a conductivity many times greater than the one not nickel-plated. The non-conductive oxide or hydrates should then be mixed with this nickelplated graphite and be put be tween perforated metal plates in the known manner in order to form electrodes. Instead of nickel, any other metal that is indifferent in the electrolyte and that does not occlude oxygen may be used, and instead of graphite any other conductive kind of carbon. I

'Il'aving now described my invention, what I claim as new, and desire to secure by Letters'Patent,is as followsi 1. An electrode for secondary batteries contalning an active mass mixed with small t e eentiremass.

containing an active mass mixed with flake graphite having a thin coating of a metal that does not occlude oxygen and that is insoluble in the electrolyte, substantially as described.

4.. An electrode for reversible secondary batteries having an alkaline electrolyte, said electrode containing an active mass of oxygen compounds of a metal mixed with flake graphite, the particles of which have a thin coatin of nickel, said coating and active mass insoluble in theele'ctrolyte, substantially as described.

5. An electrode for reversible secondary batteries having an alkaline electrolyte, said electrode containing a suitable active mass mixed with particles of carbon having a coating-of a metal that does not occlude oxygen and hat is insoluble in the electrolyte under all conditions of working, substantially as described.

6. An electrode for reversible secondary batteries having an alkaline electrolyte, said electrode containing a suitable active mass mixed with small particles of graphite having a thin coating of a metal that does not occlude oxygen and that is insoluble in the electrolyte under all conditions of working, substantially as described.

7. An electrode for reversible secondary batteries having an alkaline electrolyte, said electrode containing an active mass. mixed with particles of crystalline graphite, said particles having a coating of a metal that does not occlude oxygen, and both metal and ssaese active mass insoluble in the electrolyte under all conditions of Working, substantially as described.

8. An electrode batteries having an alkaline electrolyte, said electrodecontaming an active mass of 0x1 gen compounds of a metal mixed with fia e gra kite the particles of the graphite coated Wit nickel, said coating and active mass in for reversible secondary soluble in the electrolyte under all conditions 7 of Working, substantially as described.-

9. An electrode for reversible galvanic batteries having an alkaline electrolyte, said;

electrode containing an active mass consisting of oxygen compounds of a metal and par ticles of graphite coated with nickel, the oxygen com ounds and the metal insoluble in the alka ine electrolyte, substantially as described.

10. An electrode for reversible secondary batteries having an alkaline electrolyte, said electrode containing an active mass consistl ing of oxygen compounds of metals and particles of graphite having a plating of a metal thereon, said metal plating not occluding oxygen, and both the oxygen compounds and metal plating insoluble in the electrolyte under all conditions of working, substantially as described.

1].. A new product comprising particles of graphite plated with a metal that is insoluble in alkali and that does not occlude oxygen.

graphite, nickel plated.

13. A new product com ')rising nickelplated flakes of graphite substantially as set forth.

In testimony that I claim the foregomgas my invention, I have signed my name in presence of two subscribing witnesses.

ERNST WALDEMAR JUNGNEK.

YVitnesses ADOLPF BERcLUNn, T. Born.

' 12. A new product comprising particles of 

